JP2005057802A - Apparatus and method for video reproduction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To receive normal data from an arbitrary transmission data stream in a short period of time even without knowing in advance a parameter required for a receiver terminal to receive each of transmission data streams. <P>SOLUTION: Parameter information such as the encoding rate of convolution codes in each transmission data stream and an interleaving size is time division-multiplexed in a synchronizing signal while being spread with the same synchronization spreading code as a spreading code used for a synchronizing process of the spreading code. Therefore, as long as the synchronizing signal is being received, the parameter information is acquired regardless of the reception of each transmission data stream. Parameters for the respective parts of a receiver are set on the basis of the parameter information of transmission data streams acquired by receiving the synchronizing signal, thereby easily and speedily performing the receiving process of transmission data streams. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a code division multiplexing (CDM) transmission system and a receiving apparatus for the system, and more particularly to a technique for synchronous reproduction of a plurality of transmission data sequences to be multiplexed.

  As is well known, in code division multiplexing transmission, a plurality of transmission data sequences are subjected to frequency spread modulation using different spreading codes for each sequence, and these plurality of modulated signals are superimposed on the same frequency and transmitted. In such code division multiplex transmission, as a means for facilitating spreading code synchronization processing at the receiving terminal, a signal modulated only with a specific spreading code known on the receiving side is the same as other frequency spread modulation signals. A method of superimposing and transmitting on the frequency is used.

  In general, individual transmission data sequences that are code-division multiplexed are subjected to error correction coding and interleaving. Parameters such as the coding rate of the error correction code and the length of interleaving can be changed for each transmission data sequence.

  A convolutional code or a block code is used for the error correction code, and a convolutional interleaving or a block interleaving is used for interleaving. When each process of the punctured code, convolutional code, convolutional interleaving, and block interleaving of the convolutional code is selectively set on the transmission side, it is necessary to synchronize the blocks and the number of delay stages on the reception side. For this reason, a method is employed in which a synchronization word is inserted into each transmission data sequence at the time of transmission, and synchronization is achieved by detecting the synchronization word at the receiving terminal.

  As described above, in code division multiplex transmission, it is possible to change parameters such as the coding rate of error correction codes and the length of interleaving for each transmission data sequence. If it is not known, a complicated process such as trying to receive while changing parameters until normal data can be received is required, so that it takes a long time to output normal data.

  Further, as described above, it is necessary to insert a synchronization word in order to synchronize an error correction code or interleave, but since a synchronization word is inserted independently for each transmission data sequence, When switching to reception of another transmission data sequence, since the synchronization word has to be detected again, it takes a considerable time to switch.

  Further, in the above-described code division multiplexing transmission, since a receiving terminal receiving a certain transmission data sequence does not receive a transmission data sequence other than the transmission data sequence, it is common to all receiving terminals. When transmitting this information, it is necessary to transmit the same information to all transmission data sequences.

  The present invention has been made in consideration of the above circumstances, and normal data can be obtained from an arbitrary transmission data sequence in a short time even when parameters necessary for reception of each transmission data sequence are not known in advance at the receiving terminal. A first object is to provide a code division multiplex transmission system that can be received.

  In addition, when error correction codes and interleaving are applied to each transmission data sequence, and a synchronization word is required for their synchronization, it is not necessary to redetect the synchronization word even if the received transmission data sequence is switched. A second object is to provide a code division multiplexing transmission system.

  Furthermore, even if transmission data sequences being received at each receiving terminal are different, it is possible to transmit and receive common information to all or specific receiving terminals without including common information in all transmission data sequences. A third object is to provide a code division multiplexing transmission system that can be used.

  The code division multiplex transmission system of the present invention that solves the above problems has the following characteristic configuration.

  (1) A spread code synchronization signal for facilitating synchronization of spreading codes on the receiving side is subjected to frequency spread modulation using a known spreading code on the receiving side, and code division is performed together with frequency spread modulation signals of a plurality of transmission data sequences In a code division multiplex transmission system that multiplexes and transmits, information related to the structure of the transmission data sequence or information related to synchronization is time-division multiplexed to the spreading code synchronization signal, and the time-division multiplexed signal is transmitted to a known spreader on the receiving side. The frequency spread modulation is performed using a code, and the frequency spread modulation signal is code-division multiplexed and transmitted together with the frequency spread modulation signals of the plurality of transmission data sequences as a synchronization signal.

  (2) A spread code synchronization signal for facilitating synchronization of spreading codes on the receiving side is frequency spread modulated using a known spreading code on the receiving side, and code division is performed together with frequency spread modulation signals of a plurality of transmission data sequences In a code division multiplex transmission system for multiplexing and transmitting, information on the structure of the transmission data sequence or information on synchronization is subjected to frequency spread modulation using a known spreading code on the receiving side, and frequency spreading of the signal for spreading code synchronization is performed. Time-division multiplexing with a modulation signal is performed, and this time-division multiplexing signal is code-division multiplexed and transmitted together with the frequency spread modulation signals of the plurality of transmission data sequences as a synchronization signal.

  (3) The spread code synchronization signal for facilitating synchronization of the spread code on the reception side is frequency spread modulated using a known spread code on the reception side, and code division is performed together with the frequency spread modulation signals of a plurality of transmission data sequences In a code division multiplexing transmission system for multiplexing and transmitting, information common to all or a specific receiving terminal is time division multiplexed on the spreading code synchronization signal, and this time division multiplexed signal is spread by a known spreading code on the receiving side. The frequency spread modulation is performed using the frequency spread modulation signal, and the frequency spread modulation signal is code-division multiplexed and transmitted together with the frequency spread modulation signals of the plurality of transmission data sequences as a synchronization signal.

  (4) A spread code synchronization signal for facilitating synchronization of spreading codes on the receiving side is subjected to frequency spread modulation using a known spreading code on the receiving side, and code division is performed together with frequency spread modulation signals of a plurality of transmission data sequences In a code division multiplex transmission system that multiplexes and transmits, information that is common to all or a specific receiving terminal is subjected to frequency spread modulation using a known spreading code on the receiving side, and frequency spreading modulation of the spreading code synchronization signal The signal is time-division multiplexed with a signal, and the time-division multiplexed signal is code-division multiplexed and transmitted together with the frequency spread modulation signals of the plurality of transmission data sequences as a synchronization signal.

  (5) In the configuration of any one of (1) to (4), the information related to the configuration of the transmission data sequence includes at least an encoding rate of an error correction code or an interleaving length of each of the plurality of transmission data sequences. Parameter information is included.

  (6) In the configuration of any one of (1) to (4), the information related to synchronization of the transmission data sequence includes at least an error correction code of each of the plurality of transmission data sequences or a synchronization word necessary for interleaving synchronization. It is characterized by including.

  (7) In the configuration of (6), the transmission period of the synchronization word included in the synchronization signal is the least common period of the minimum synchronization word transmission period required for error correction code or interleave synchronization in each of the plurality of transmission data sequences And the timing of error correction coding or interleaving of all transmission data sequences to be code division multiplexed is adapted to the synchronization word.

  (8) In any one of the constitutions (1) to (4), region identification information is included in information common to the receiving terminal, and the receiving terminal capable of receiving common information is limited to a specific region. And

  (9) In any configuration of (1) to (4), a receiving terminal capable of receiving common information is registered in advance, including group identification information registered in advance in information common to the receiving terminal. It is characterized by specifying the terminal of the group subscriber.

  (10) In any one of the constitutions (1) to (4), an activation signal for prompting activation of the receiving terminal is included in the information common to the receiving terminal.

  (11) In the configuration of any one of (1) to (4), the length of the spreading code synchronization signal is longer than the maximum value of the propagation delay time difference between the paths expected from the multipath propagation environment. The transmission cycle of the code synchronization signal is characterized by being shorter than the fluctuation cycle of fading that occurs on the transmission path.

  (12) In the configuration of any one of (1) to (4), for the synchronization signal, the number of spreading code synchronization signals accommodated in one frame is set to the bit interleaving depth in the plurality of transmission data sequences. The number is an integral multiple of.

  (13) In the configuration of any one of (1) to (4), for each of the plurality of transmission data sequences, a timing at which a bit having a delay time 0 of the bit interleave appears is immediately after the spreading code synchronization signal. It is characterized by doing so.

  (14) In the configuration of any one of (1) to (4), the number of frames in one superframe of the synchronization signal is determined according to MPEG-, regardless of the coding rate of the convolutional codes of the plurality of transmission data sequences. The TS packets defined by 2 Systems are selected so that an integer number is included in one superframe, and the TS packet synchronization bytes and punctured codes defined by MPEG-2 Systems of each of the plurality of transmission data sequences are punctured The head of the pattern is made to correspond to a predetermined position of the first frame in the one superframe of the synchronization signal.

  A receiving apparatus that receives a code division multiplexed signal transmitted by the code division multiplexing transmission method of any one of (1) to (4) has the following characteristic configuration.

  (15) A receiving apparatus for receiving a code division multiplexed signal transmitted by a code division multiplexing system having the configuration of (1) or (2), wherein the receiving apparatus receives the synchronization signal modulated by frequency spread modulation, and a known spreading code And the information on the structure of the transmission code sequence or the information on the synchronization is reproduced.

  (16) A receiving apparatus for receiving a code division multiplexed signal transmitted by a code division multiplexing system having the configuration of (3) or (4), receiving the synchronization signal modulated by frequency spread modulation, And spreading signal synchronization signals, or information common to all or a specific receiving terminal.

  (17) In the configuration of (15), a receiving device that receives a code division multiplexing signal transmitted by the code division multiplexing scheme according to the configuration of (5), wherein the plurality of signals included in the information related to the configuration of the transmission data sequence Any transmission data sequence error correction or deinterleaving processing is performed using the parameter information of the coding rate of the error correction code or the interleaving length of each transmission data sequence.

  (18) In the configuration of (15), the receiving device receives a code division multiplexed signal transmitted by the code division multiplexing transmission method of (6), and the plurality of signals included in the information related to synchronization of the transmission data sequence It is characterized by performing error correction or deinterleaving synchronization of an arbitrary transmission data sequence by using a synchronization word necessary for error correction or interleaving synchronization of each transmission data sequence.

  (19) In the configuration of (15), a receiving device that receives a code division multiplexed signal transmitted by the code division multiplexing transmission method of (7), wherein a transmission period of a synchronization word included in the synchronization signal The method is characterized in that a synchronization word transmission period required for error correction or interleaving synchronization in an arbitrary transmission data sequence is obtained to determine error correction or deinterleaving processing timing.

  (20) In the configuration of (16), a receiving device that receives a code division multiplexing signal transmitted by the code division multiplexing transmission method of (8), separately acquires the location information of the own device, and the synchronization signal It is characterized in that it is determined whether or not the device corresponds to the area identification information included in the common information, and the common information is received and reproduced if it corresponds.

  (21) In the configuration of (16), a receiving device that receives a code division multiplexing signal transmitted by the code division multiplexing transmission method of (9), separately acquires registration group information of the own device, and receives the synchronization signal It is characterized in that it is determined from the group identification information included in the common information whether or not the registered group of its own device is applicable, and the common information is received and reproduced if applicable.

  (22) In the configuration of (16), the receiving device receives a code division multiplexed signal transmitted by the code division multiplexing transmission method of (10), and prompts activation of a receiving terminal included in the common information It is activated by an activation signal.

  (23) In the configuration of (15) or (16), a receiving device that receives a code division multiplexed signal transmitted by the code division multiplexing transmission method of (11), wherein the spreading code in one frame of the synchronization signal A depth of bit interleaving in an arbitrary transmission data sequence is obtained from the number of synchronization signals, and deinterleaving processing of the transmission data sequence is performed.

  (24) In the configuration of (15) or (16), a receiving device that receives a code division multiplexed signal transmitted by the code division multiplexing transmission method of (12), wherein the bit immediately follows the spreading code synchronization signal It is characterized in that it is determined that the bit has a delay time of 0 for interleaving, and the deinterleaving process for the transmission data sequence is performed.

  That is, in order to achieve the above first to third objects, the code division multiplexing transmission system according to the present invention has been conventionally known on the receiving terminal side as means for facilitating spreading code synchronization processing at the receiving terminal. Focusing on the fact that all receiving terminals receive a signal modulated only with a specific spreading code (hereinafter referred to as “spreading code for synchronization”) in parallel with the reception of each transmission data sequence. Parameters such as coding rate and interleaving length of the error correction code of each transmission data sequence of the first purpose, synchronization word necessary for synchronization of the error correction code and interleaving of each transmission data sequence of the second purpose, And at least one of common information (hereinafter referred to as “parameters”) for all or a specific receiving terminal as the third purpose is spread with a synchronization spreading code, and this frequency spread modulation signal Time division multiplexing the signal modulated only by synchronizing the spread code, so that superimposed on the same frequency as the frequency spread modulation signal at this time the transmission data sequence division multiplex signal as a synchronization signal.

  However, when performing the above time-division multiplexing, the length of the spreading code synchronization signal is set between each path expected from the multipath propagation environment so as not to hinder the spreading code synchronization processing at the receiving terminal. Is longer than the maximum value of the propagation delay time difference, and the transmission period of the spreading code synchronization signal is shorter than the fluctuation period of fading that occurs on the transmission path.

  In addition, the transmission period of the above-mentioned synchronization word is the least common multiple of the minimum synchronization word transmission period necessary for synchronization of error correction codes, interleaves, etc. in each transmission data series, and all transmissions that are code division multiplexed The timing of error correction coding and interleaving of the data series is adjusted to the synchronization word.

  By configuring as described above, it becomes possible for all the receiving terminals to receive parameters and the like in parallel with the reception of each transmission data sequence without hindering the spreading code synchronization processing at the receiving terminals. By using information such as the coding rate of the error correction code of each received transmission data sequence and the length of the interleave, reception processing such as decoding and deinterleaving of the error correction code of each transmission data sequence can be performed easily and It can be done quickly.

  Also, since the timing of error correction coding and interleaving in each transmission data sequence is synchronized with the above synchronization word, there is no need to synchronize each transmission data sequence, and error correction coding in each transmission data sequence In addition to the fact that synchronization such as interleaving can be performed quickly, re-synchronization when switching to reception of another transmission data sequence becomes unnecessary, and the time required for switching can be shortened.

  Furthermore, since all or specific receiving terminals continuously receive common information for all or specific receiving terminals, all or specific reception without transmitting the same information to all transmission data sequences Common information can be transmitted to the terminal.

  In the present invention, in a broadcast or transmission system using a code division multiplexing transmission system, the received signal has a significant amplitude and frequency due to the Doppler effect and fading, as in the case of receiving a signal in a moving body moving at high speed. Even in an environment where fluctuations occur, the coding rate of the error correction code of each transmission data sequence that is code division multiplexed, the length of interleaving, etc. Parameters, error correction codes of each transmission data sequence, synchronization words necessary for interleaving synchronization, and information common to all or a specific receiving terminal, etc. The data can be received in parallel, and the error correction code of each transmission data sequence can be recovered using the received information and synchronization word. In addition, it is possible to easily and quickly perform reception processing such as deinterleaving, and synchronization that can reduce the amount of data when common information is transmitted to all or specific receiving terminals. The signal is transmitted together with a plurality of transmission data sequences by code division multiplexing.

  Therefore, according to the present invention, (1) normal data can be received from an arbitrary transmission data sequence in a short time even when parameters necessary for reception of individual transmission data sequences are not known in advance at the receiving terminal. (2) When an error correction code or interleave is applied to each transmission data sequence, and a synchronization word is necessary for their synchronization, the synchronization word is detected again even if the received transmission data sequence is switched. (3) Even if transmission data sequences being received at different receiving terminals are different, common information is transmitted to all or specific receiving terminals without including common information in all transmission data sequences. Therefore, it is possible to provide a code division multiplex transmission system having an effect that it can be received.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows the format structure of a synchronization signal used in the code division multiplexing system according to the present invention. For example, as shown in FIG. 1A, this synchronization signal is a signal having a length of 125 μsec (hereinafter referred to as “pilot symbol (PS)”) modulated only by a synchronization spreading code every 250 μsec. This is a combination of a 125 μsec long frequency spread modulation signal (D) generated by spreading data such as various parameters with the same synchronization spreading code as the pilot symbol, and time-division-multiplexing both signals as a pair. In this synchronization signal, for example, as shown in FIG. 1 (b), one frame is composed of 51 pairs of pilot symbols and spread spectrum modulation signals as one unit, and one super frame is composed of 6 frames as one unit. Configure.

When each frequency spread modulation signal in one frame of the synchronization signal is D ₁ , D ₂ , D ₃ ,..., D _{51 in} order from the top, D _{1 to} D ₅₁ are, for example, the following information.

D ₁ is a synchronization word having a fixed pattern for frame synchronization, for example, a frequency spread modulation signal generated by spreading “01101010101101010101100110001010” with a spreading code for synchronization.

D ₂ is a synchronization word indicating the frame number in the super frame. For example, as shown in FIG. 2, the frame starts from 0x0 and increases by 1 every frame, and then becomes 0x0 in the next frame of 0x5. A value obtained by spreading a 4-bit binary number that is repeated eight times with a spreading code for synchronization is assumed to be generated.

For example, as shown in FIG. 3, D _{3 to} D ₅₀ are identification information (7 bits), receiver activation signal (1 bit), CDM channel configuration information (568 bits), receiver activation additional information (48 bits), and error correction. Data composed of CRC check bits (16 bits) and Reed-Solomon (RS) code check bytes (128 bits) are byte interleaved and convolutionally encoded, and then spread with a synchronization spreading code to generate a frequency spread modulation signal. The signal is divided every 125 μsec.

  Here, the identification information is information for identifying the content of the subsequent data, and is defined as shown in Table 1, for example.

  The receiver activation signal is a signal for prompting activation of the receiver in an emergency or the like. For example, it is “1” when it is desired to prompt activation of the receiver, and “0” otherwise.

  The CDM channel configuration information is composed of, for example, a starting CDM channel number (8 bits) and 10 channels of CDM channel individual configuration information (56 × 10 bits) as shown in FIG. Individual configuration information consists of interleave mode (4 bits), convolution mode (4 bits), TS-ID (16 bits), reserve (3 bits), minimum PID value (13 bits), version number (3 bits), maximum PID value (13 bits) Shall be.

  The start CDM channel number indicates, for example, which CDM channel information the first CDM channel individual configuration information in the CDM channel configuration information is, and the nth CDM channel individual configuration information has a CDM channel number. This is information on the CDM channel of (starting CDM channel number + n−1).

  The interleave mode is data for designating the interleave size of the CDM channel, and takes values as shown in Table 2, for example.

  The convolution mode is data defining the coding rate of the convolutional code of the CDM channel, and takes values as shown in Table 3, for example.

  The TS-ID is, for example, data indicating a transport stream number transmitted by the CDM channel. When there is no data to be transmitted, TS-ID = 0xFFFF, for example.

  The reserve is an area used as a future extension area of CDM channel configuration information, for example.

  The PID minimum value is, for example, data indicating the minimum value of the PID range in a TS packet transmitted by the CDM channel. When the same PID range is assigned to another CDM channel, a plurality of CDM channels are bundled. Indicates that the TS is configured.

  The version number is data that increases by one each time the setting is changed, for example.

  The PID maximum value is, for example, data indicating the maximum value of the PID range in a TS packet transmitted by the CDM channel. When the same PID range is assigned to another CDM channel, a plurality of CDM channels are bundled. Indicates that the TS is configured.

  The additional information at the time of receiver activation is effective as auxiliary information for the receiver activation signal. For example, as shown in FIG. 5, type information (4 bits) indicating the level of urgency, the target area for emergency broadcasting, and the like. The area identification information (12 bits) indicating the emergency broadcast program TS-ID (16 bits), and the emergency broadcast program number (16 bits).

The CRC check bit is information for checking a data error. For example, the check bit of the CRC is used for an error check by CRC with a generator polynomial of G (x) = x ¹⁶ + x ¹² + x ⁵ +1.

The check byte of the Reed-Solomon code is, for example, code generation polynomial g (x) = (x + λ ⁰ ) (x + λ ¹ ) (x + λ ² )... (X + λ ¹⁵ ); λ = 02h, field generation polynomial P (x) = x ⁸ In the Reed-Solomon (255, 239) code of + x ⁴ + x ³ + x ² +1, a shortened read generated by adding “00h” of 159 bytes before the input data byte and removing the leading 159 bytes after encoding The inspection byte when the Solomon (96, 80) code is used.

In D _{3 to} D ₅₀ , various information can be transmitted as extended information (616 bits) as shown in FIG. 6 in addition to the CDM channel configuration information and receiver startup additional information shown in FIG. Shall.

_D51 is a reserved area, and is a signal modulated only by a synchronization spreading code, for example.

  The CDM channel configuration information, receiver startup additional information, extension information, and the like described above are configured as shown in FIG. 7, for example, in units of one superframe. The symbol * in the figure indicates a receiver activation signal.

  FIG. 8 is a block diagram illustrating a configuration of a CDM transmission signal generation apparatus that performs generation of a synchronization signal having the above-described format configuration and code division multiplexing of the first to nth data sequences.

  In FIG. 8, first, a circuit configuration for generating a synchronization signal and performing frequency spread modulation will be described.

  Various data such as parameters in the first to nth transmission data sequences transmitted as D3 to D50 are encoded by the Reed-Solomon (96, 80) encoding circuit 11 and byte interleaved by the byte interleaving circuit 12. After that, the data is compressed and encoded by the convolutional encoding circuit 13, further converted into parallel data by the serial / parallel conversion circuit 14, and sent to the changeover switch (SW) 15.

This change-over switch 15 is data of “0”, a fixed pattern, and a frame number for generating the transmission data and pilot symbols PS, D ₁ , D ₂ , and D ₅₁ supplied from a system different from the transmission data. Is selectively derived, and the output data is diffused by the Walsh code (W ₀ ) in the EX-OR (exclusive OR) circuit 16 in the first stage, and further in the next stage. The EX-OR circuit 17 performs spreading with a pseudo-random code to generate a synchronization signal having the above format configuration. This synchronization signal is QPSK modulated by the QPSK modulation circuit 18 and supplied to the synthesis circuit 19 as a frequency spread modulation signal of the synchronization signal.

  Next, a circuit configuration for performing frequency spread modulation of the first to nth transmission data series will be described.

The first to nth transmission data series are encoded by Reed-Solomon (204, 188) encoding circuits 211 to 21n, byte interleaved by byte interleaving circuits 221 to 22n, and then convolutional encoding circuit 231. Are encoded by ˜23n, bit interleaved by bit interleave circuits 241˜24n, and converted into parallel data by serial / parallel conversion circuits 251˜25n. Subsequently, the first-stage EX-OR circuits 261 to 26n are spread with Walsh codes (W _{1 to} W _n ), and the next-stage EX-OR circuits 271 to 27n are further spread with pseudo-random codes, and the QPSK modulation circuit QPSK modulation is performed at 281 to 28n, and the resultant signal is supplied to the synthesis circuit 19 as a frequency spread modulation signal of the first to nth transmission data series.

  The synthesizing circuit 19 multiplexes and synthesizes the frequency spread modulation signal of the synchronization signal generated as described above and the frequency spread modulation signal of the first to n-th transmission data series at the same frequency. A code division multiplexed signal is generated.

  In the configuration shown in FIG. 8, in the generation of the synchronization signal, the information spread on the pilot symbols, D1, D2, and D51 areas and the information on the D3 to D50 areas are time-division multiplexed, and then spread spectrum modulation is performed using spreading codes. However, the present invention is not limited to this. For example, even if each information is first subjected to frequency spread modulation with the same spreading code and then time-division multiplexed, the same synchronization signal is generated. be able to.

  In the above configuration, the overall operation will be described below.

First, in the synchronization signal generation / modulation circuit system, “0” is selected by the changeover switch 15 during the period of the pilot symbols PS and D ₅₁ , and a signal modulated only by the synchronization spreading code is generated. During the period D ₁ , a fixed pattern is selected by the changeover switch 15, and a spread spectrum modulation signal is generated by spreading the fixed pattern using a synchronization spreading code. In the period D ₂ , the frame number is selected by the changeover switch 15, and a frequency spread modulation signal is generated by spreading the frame number with the spreading code for synchronization. In the period from D _{3 to} D ₅₀ , serial / parallel conversion output is selected by the changeover switch 15, and data such as CDM channel configuration information is Reed-Solomon encoded, byte interleaved, and, for example, a constraint length of 7, a coding rate of 1/2 A spread spectrum modulation signal is generated by spreading the convolutionally encoded signal with a synchronization spreading code.

Here, in the byte interleaving method of D _{3 to} D ₅₀ , for example, as shown in FIG. 9, convolutional interleaving with a period of 12 is used in units of bytes, and the position of the first byte of the data shown in FIG. 3 or FIG. , The delay amount D of the byte at the n-th position is interleaved so as to be given by D = 12 × 16 × I (I is an integer from 0 to 11 when n is divided by 12). The

  On the other hand, in the first to nth transmission data series modulation circuit systems, for example, Reed-Solomon (204, 188) encoding, byte interleaving, convolutional encoding, bit interleaving for MPEG-2 TS (transport stream) packets. After the above processes are performed, the transmission data sequence is spread with a spreading code and subjected to QPSK modulation to generate a transmission data sequence frequency spread modulation signal.

Here, the Reed-Solomon code of the transmission data sequence includes, for example, a code generator polynomial g (x) = (x + λ ⁰ ) (x + λ ¹ ) (x + λ ² )... (X + λ ¹⁵ ); λ = 02h, a field generator polynomial P (x ) = x ⁸ + x ⁴ + x ³ + x ² +1 Reed-Solomon (255,239) code, generated by adding 51 bytes “00h” before the input data byte and removing the first 51 bytes after encoding The shortened Reed-Solomon (204, 188) code is used.

  Further, for example, as shown in FIG. 10, a convolution method with a cycle of 12 is used for each byte of the transmission data sequence, and the position of the synchronization byte is set to 0 in the TS packet to which the Reed-Solomon code is added. Is interleaved so that the delay amount D of the byte at the n-th position is given by D = 12 × 17 × I (I is an integer from 0 to 11 when n is divided by 12).

  In addition, for example, a convolutional code with a constraint length of 7 and a coding rate of 1/2 and a punctured code with a coding rate of 2/3, 3/4, and 5/6 are used for convolutional coding of the transmission data sequence. It is done.

For bit interleaving of the first to n-th transmission data sequences, for example, as shown in FIG. 11A, a divisional convolutional interleaving scheme with a period of 51 is used for each bit. The delay amount of bit interleaving is, for example, that the delay amount of bits on the Ich side of QPSK modulation is 0 in the transmission data sequence transmitted simultaneously with the synchronization signal immediately after the synchronization signal is switched from D ₁ to the pilot symbol, The bit delay amount D after n bits is D = 51 × (I + 17 × J) × m (where I is rounded down to the quotient when the remainder when n is divided by 51 is divided by 3) Value, an integer from 0 to 16, J is a remainder when n is divided by 3, and an integer from 0 to 2, and m is an interleave size).

  FIG. 11B shows a circuit configuration of interleaving and deinterleaving in this case. In FIG. 11 (b), an interleave circuit A and a deinterleave circuit B each include an input changeover switch SWin and an output changeover switch SWout that are interlocked with each other, and a plurality of interleave circuits that are interposed between predetermined lines of 51 lines selected by these switches. The delay amount of each delay element D is provided so that the total delay amount in lines sequentially selected by both circuits A and B is the same, and the bit interleave depth is 17 Is selected.

As is clear from this circuit configuration, it is necessary to synchronize every time the transmission data sequence is switched so that the deinterleave selection line on the reception side is always the same as the interleave selection line on the transmission side. Therefore, the number of pilot symbols in one frame is set to 51, and it is selected to be an integer multiple of the bit interleave depth 17 in each transmission data sequence, and the timing at which the bit of the interleave delay time 0 appears is immediately after D ₁ of the synchronization signal. And Thus, by using D ₁ of the fixed pattern (synchronization word) that appears once in one frame, it becomes possible to easily and quickly synchronize the bit interleave of each transmission data series.

The spreading code for the transmission data sequence is a spreading code different from the spreading code for synchronization, and when there are a plurality of transmission data sequences, a spreading code unique to each transmission data sequence is used. For example, the synchronization spreading code is generated by exclusive OR of the Walsh codes W ₀ shown in Tables 4 and 5 and the pseudo random code generated from the pseudo random code generation circuit shown in FIG. and those using that code, the spreading code of the n-th transmission data sequence, a pseudo-random code generated from the pseudo-random code generating circuit shown in tables 4 and W _n and 12 of Walsh codes shown in Table 5 It is assumed that a code generated by exclusive OR is used.

Incidentally, the pseudo-random code generating circuit shown in FIG. 12 is a general arrangement, wherein a shift register with delay elements x ₁ ~x ₁₂ of 12 stages, exclusive of the output of x ₁₁ and x ₁₂ EX-OR circuit G ₁ for obtaining the sum, EX-OR circuit G ₂ for obtaining an exclusive OR of the output of the EX-OR circuit G ₁ and x _8, and the output of the EX-OR circuit G ₂ and x ₆ Is provided with an EX-OR circuit G ₃ for obtaining the exclusive OR of the two and outputting them to the first-stage delay element x ₁ .

In the configuration of FIG. 12, the pseudo-random code generation method is such that the initial value of the shift register (x _{1 to} x ₁₂ ) is “010101100000” and the delay elements x _{1 to} x ₁₂ are reset and shifted every 2048 bits. A method of forcibly returning the contents of the registers (x _{1 to} x ₁₂ ) to the initial value is used.

The reset timing of the shift registers (x _{1 to} x ₁₂ ) is, for example, the pilot symbol or the head of D _{1 to} D ₅₁ , and is the same for the pseudo-random code used for the spreading code for synchronization and the spreading codes for all transmission data sequences This is the reset timing. For the Walsh codes W ₀ , W ₁ ,..., W _n ,..., For example, the head codes in Tables 4 and 5 are output at this reset timing.

Finally, the synchronization signal and the frequency spread modulation signals of the first to nth transmission data sequences are combined to generate a code division multiplexed signal. During synthesis, the transmission data, for example D ₂ of the synchronization signal immediately after switching to the pilot symbols from the time a frequency spread modulation signal generated by spreading a synchronous spread code of 0x00000000, are transmitted synchronizing signal and the same time The bit that comes to the Ich side of the QPSK modulation in the sequence is a 2-bit output from the convolutional coding circuit when the delay element of the convolutional coding circuit holds 6 bits from the MSB of the synchronization byte of the TS packet. One of these bits is synthesized at a timing that is the leading phase of the punctured pattern.

  The configuration of the receiver that receives the code division multiplexed signal generated as described above is basically the configuration opposite to that on the transmission side. Specifically, it is configured as shown in FIG.

  In FIG. 13, a code division multiplexed signal input from a transmission path (not shown) is subjected to quadrature detection by the quadrature detection circuit 31 and then supplied to the propagation path response measurement circuit 32. This propagation path response measurement circuit obtains the synchronization information of the spread code by analyzing the propagation path response characteristics of the input signal in the above-described pilot symbol portion using a matched filter or the like (not shown). The obtained spreading code synchronization information and the like are supplied to the RAKE combining circuits 330 to 33n.

Each of the RAKE combining circuits 330 to 33n uses a spreading code (pseudorandom code + Walsh code (W _{0 to} W _n )), synchronization information of the spreading code, and the like. The transmission data series is separated and demodulated. Of these, the synchronization signal obtained by the RAKE combining circuit 330 is supplied to the frame and superframe timing extracting circuit 34, where by utilizing the D ₁ and D ₂ from the synchronization signal frame and the timing of the superframe are extracted, respectively Are generated.

The synchronization signal obtained by the RAKE combining circuit 330 is supplied to the D _{3 to} D ₅₀ extraction circuit 35. The D _{3 to} D ₅₀ extraction circuit 35 identifies D _{3 to} D ₅₀ regions in the synchronization signal based on the frame timing signal, and extracts data inserted in these regions. The data in the areas D _{3 to} D ₅₀ is Viterbi decoded by the Viterbi decoding circuit 36 and supplied to the byte deinterleaver 37.

This byte interleaver 37 performs byte deinterleaving on the Viterbi-decoded data in the regions D _{3 to} D ₅₀ in synchronization with the frame timing signal, and its output is supplied to the RS decoding circuit 38. The RS decoding circuit 38 decodes the Reed-Solomon (96, 80) code from the Viterbi decoding output based on the frame timing signal. The decoding output is supplied to the parameter setting circuit 39 and also detects the receiver activation signal. This is supplied to the circuit 40 and the common information reproduction circuit 41.

  The parameter setting circuit 39 extracts parameter information such as the interleave size and coding rate from the RS decoding output. The receiver activation signal detection circuit 40 detects a receiver activation signal from the RS decoding output and generates an activation signal when the signal is detected. The activation signal is supplied to the common information reproduction circuit 41. Is done. When receiving the activation signal, the common information reproduction circuit 41 takes in the RS decoded output and reproduces the common information in the synchronization signal (for example, additional information at the time of receiver activation shown in FIG. 5). The reproduction result is displayed. Output to the processing system. In this case, when the area identification information is added to the common information, the position information obtained from the GPS system or the like is taken in, and the reproduction is performed only when the position of the receiver corresponds to the area specified by the area identification information. Shall.

  On the other hand, the transmission data series demodulated by the RAKE combining circuits 331 to 33n are converted into serial signals by the parallel / serial converters 421 to 42n, respectively, and then supplied to the bit deinterleavers 431 to 43n. These bit interleavers 431 to 43n perform parameter setting based on information such as the interleave size obtained by the parameter setting circuit 39, and then perform bit deinterleaving of the transmission data sequence in synchronization with the frame timing signal. The output is supplied to the Viterbi decoding circuits 441 to 44n.

  The Viterbi decoding circuits 441 to 44n perform parameter setting based on parameter information, and perform Viterbi decoding of the bit deinterleave output in synchronization with the superframe timing signal. The decoded output is a byte deinterleaver 451. ˜45n, RS decoding circuits 461 to 46n perform byte interleaving processing and Reed-Solomon (204,188) code decoding processing in synchronization with the superframe timing signal, thereby taking out the first to nth transmission data sequences. be able to.

  By using the synchronization signal described above, the following effects can be obtained.

  First, pilot symbols that are modulated only with a spreading code for synchronization are inserted into the synchronization signal every 250 μsec. For this reason, even if a frequency fluctuation sufficiently smaller than 1/250 μsec = 4 kHz occurs during mobile reception, there is no problem in the synchronization processing of the receiving terminal. For example, when 2.6 GHz is used as the carrier frequency, a frequency fluctuation of 4 kHz is equivalent to about 1700 km / h when converted to a speed, so that practically no trouble occurs in the receiving terminal synchronization processing. .

  The pilot symbol length modulated only by the synchronization spreading code is 125 μsec. Therefore, the signal delay time that can be analyzed by the receiver is 125 μsec. This corresponds to a distance of 37 km. This value is sufficient when considering that, for example, in a satellite broadcasting system that uses a code division multiplex transmission system, the gap filler used for countermeasures for dead zones such as shadows of buildings is aimed at a service range with a radius of several kilometers. .

  Furthermore, in the synchronization signal, the parameter information such as the convolutional code rate of each transmission data sequence and the interleave size is spread with the same spreading code used for the spreading code synchronization process. Time-division multiplexed. For this reason, as long as the synchronization signal is received, the parameter information can be acquired regardless of the reception of each transmission data sequence. Therefore, by setting the parameters of each part of the receiver based on the parameter information of each transmission data sequence acquired by receiving the synchronization signal, the reception processing of each transmission data sequence can be performed easily and quickly.

On the other hand, the number of pilot symbols 51 in one frame is selected to be an integral multiple of the bit interleaving depth 17 in each transmission data sequence, and the timing at which the bit of the interleaving delay time 0 appears is immediately after D ₁ of the synchronization signal. It has become. For this reason, by using D ₁ of a fixed pattern that appears once in one frame, it is possible to easily and quickly synchronize bit interleaving of each transmission data sequence.

Further, the number of frames 6 in one superframe can be any coding rate of 1/2, 2/3, 3/4, 5/6, and 7/8. Even if it is set, it is selected so that an integer number of MPEG-2 TS packets can be included in one superframe. In addition, the synchronization byte of the MPEG-2 TS packet of each transmission data series and the beginning of the punctured pattern of the punctured code are determined to be immediately after D ₂ of the first frame in the synchronization signal 1 superframe. . Therefore, by counting the frame number using D ₂ , synchronization of TS packets of each transmission data series, synchronization of byte interleaving synchronized with TS packets, and synchronization of punctured codes are performed easily and quickly. be able to.

As described above, since all transmission data sequences can be synchronized by using D ₁ and D ₂ in the synchronization signal without using information in each transmission data sequence, another transmission data Resynchronization is not required even when switching to series reception.

Further, the synchronization signal, the convolutional code rate of the code, and size, etc. of interleaving, information other than information required for reception processing of the transmission data sequence is also capable of transmitting mechanism using the region of D ₃ to D ₅₀ It has become. Thus, disaster information and the like of emergency, by placing the information to be transmitted in common to all of the receiving terminal in the area of the D ₃ to D _50, is necessary to transmit the same information to all of the transmission data sequence Absent.

  In this case, since the area identification information is included, it is also possible to specify the area and transmit the information. Furthermore, since information on TS-IDs and program numbers can also be transmitted, it is possible to automatically switch to a specific transmission data sequence for reception. In this way, by including the information of the switching destination in the synchronization signal that is always received, even if the amount of information is large and cannot be carried on the synchronization signal, the information to be transmitted is assigned to the specific transmission data sequence Thus, all or a specific receiving terminal can automatically receive.

  In the above embodiment, the region identification information is used to specify the receiving terminal that receives the common information. However, any group identification information registered in advance is used to specify the receiving terminal that receives the common information. It is also possible. As a result, services such as notification of emergency information and the like to a specific receiving terminal carrier are also possible.

The figure which shows the format structure of the synchronizing signal by the code division multiplexing system which concerns on embodiment of this invention. It illustrates a format configuration of information to be transmitted in the region D ₂ of the synchronizing signal shown in FIG. It illustrates an example of information to be transmitted in the region D ₃ to D ₅₀ of the sync signal shown in FIG. The figure which shows an example of the CDM channel structure information shown in FIG. The figure which shows an example of the additional information at the time of receiver starting shown in FIG. Shows another example of information to be transmitted in the region D ₃ to D ₅₀ of the sync signal shown in FIG. The figure which shows the structural example of 1 super-frame of the synchronizing signal shown in FIG. The block diagram which shows the structure of the CDM transmission signal generation apparatus of this embodiment. In the circuit configuration shown in FIG. 8, a diagram illustrating an example of a byte interleaved regions D ₃ to D ₅₀ of the sync signal. The figure which shows an example of the byte interleaving of a transmission data series in the circuit structure shown in FIG. The figure which shows an example of the bit interleaving of a transmission data series in the circuit structure shown in FIG. The figure which shows an example of the production | generation circuit of the pseudo random signal used with the circuit shown in FIG. The block diagram which shows the structure of the CDM transmission signal receiver of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Reed-Solomon (96,80) encoding circuit 12 ... Byte interleave circuit 13 ... Convolutional encoding circuit 14 ... Serial / parallel conversion circuit 15 ... Changeover switch 16, 17 ... EX-OR circuit 18 ... QPSK modulation circuit 19 ... Composition Circuits 211 to 21n Reed-Solomon (204, 188) encoding circuit 221 to 22n Byte interleaving circuit 231 to 23n Convolutional encoding circuit 241 to 24n Bit interleaving circuit 251 to 25n Serial / parallel conversion circuit 261 to 26n 271~27n ... EX-oR circuit 281～28N ... QPSK modulation circuit 31 ... quadrature detector 32 ... channel response measurement circuit 330～33N ... RAKE combining circuit 34 ... frame and superframe timing extracting circuit 35 ... D ₃ to D ₅₀ Extraction circuit 3 ... Viterbi decoding circuit 37 ... Byte deinterleaver 38 ... RS decoding circuit 39 ... Parameter setting circuit 40 ... Receiver activation signal detection circuit 41 ... Common information reproduction circuit 421-42n ... Parallel / serial converter 431-43n ... Bit interleaver 441-44n ... Viterbi decoding circuit 451-45n ... Byte deinterleaver 461-46n ... RS decoding circuit

Claims (25)

The spread code synchronization signal for facilitating synchronization of the spread code on the receiving side is frequency spread modulated using a known spread code on the receiving side, and code division multiplexed together with the frequency spread modulation signal of a plurality of transmission data sequences In the code division multiplex transmission system to transmit,
Information related to the structure of the transmission data sequence or information related to synchronization is time-division multiplexed onto the spreading code synchronization signal, and the time-division multiplexed signal is frequency-spread modulated using a known spreading code on the receiving side, and this frequency spreading is performed. A code division multiplexing transmission system, wherein a modulation signal is used as a synchronization signal and transmitted by code division multiplexing together with the frequency spread modulation signals of the plurality of transmission data sequences. The spread code synchronization signal for facilitating synchronization of the spread code on the receiving side is frequency spread modulated using a known spread code on the receiving side, and code division multiplexed together with the frequency spread modulation signal of a plurality of transmission data sequences In the code division multiplex transmission system to transmit,
Information on the configuration of the transmission data sequence or information on synchronization is subjected to frequency spread modulation using a known spreading code on the receiving side, and time-division multiplexed with the frequency spread modulation signal of the signal for spreading code synchronization. A code division multiplexing transmission system, wherein a signal is transmitted as a synchronization signal by code division multiplexing together with a frequency spread modulation signal of the plurality of transmission data sequences. The spread code synchronization signal for facilitating synchronization of the spread code on the receiving side is frequency spread modulated using a known spread code on the receiving side, and code division multiplexed together with the frequency spread modulation signal of a plurality of transmission data sequences In the code division multiplex transmission system to transmit,
Information common to all or a specific receiving terminal is time-division multiplexed to the spreading code synchronization signal, and the time-division multiplexed signal is frequency-spread modulated using a known spreading code on the receiving side. A code division multiplexing transmission system, wherein a signal is transmitted as a synchronization signal by code division multiplexing together with a frequency spread modulation signal of the plurality of transmission data sequences. The spread code synchronization signal for facilitating synchronization of the spread code on the receiving side is frequency spread modulated using a known spread code on the receiving side, and code division multiplexed together with the frequency spread modulation signal of a plurality of transmission data sequences In the code division multiplex transmission system to transmit,
Information common to all or a specific receiving terminal is subjected to frequency spread modulation using a known spreading code on the receiving side, and time-division multiplexed with the frequency spread modulation signal of the spreading code synchronization signal, and this time-division multiplexed signal A code division multiplex transmission system characterized in that the signal is code division multiplexed and transmitted together with the frequency spread modulation signal of the plurality of transmission data sequences as a synchronization signal.   3. The code according to claim 1, wherein the information related to the configuration of the transmission data sequence includes at least parameter information of a coding rate of an error correction code or an interleaving length of each of the plurality of transmission data sequences. Division multiplexing transmission system.   The code division multiple transmission according to claim 1 or 2, wherein the information related to synchronization of the transmission data sequence includes at least an error correction code of each of the plurality of transmission data sequences or a synchronization word required for interleave synchronization. method.   The transmission period of the synchronization word included in the synchronization signal is the least common multiple period of the minimum synchronization word transmission period necessary for synchronization of the error correction code or interleave in each of the plurality of transmission data sequences, and all of the code division multiplexed signals 7. The code division multiplex transmission system according to claim 6, wherein the error correction encoding or interleaving timing of the transmission data sequence is matched with the synchronization word.   5. The code division multiplexing transmission system according to claim 3 or 4, wherein area identification information is included in information common to the receiving terminals, and receiving terminals capable of receiving common information are limited to a specific area.   The group identification information registered beforehand in the information common to the receiving terminal is included, and the receiving terminal capable of receiving the common information is specified as the terminal of the group subscriber registered in advance. 4. Code division multiplexing transmission system according to 4.   5. The code division multiplexing transmission system according to claim 3, wherein an activation signal for prompting activation of the receiving terminal is included in information common to the receiving terminal.   The length of the spreading code synchronization signal is longer than the maximum value of the propagation delay time difference between the paths expected from the multipath propagation environment, and the transmission period of the spreading code synchronization signal is a fluctuation period of fading generated on the transmission line. 5. The code division multiplexing transmission system according to claim 1, wherein the code division multiplexing transmission system is shorter.   5. The synchronization signal, wherein the number of spreading code synchronization signals accommodated in one frame is an integer multiple of the depth of bit interleaving in the plurality of transmission data sequences. Any one of the code division multiplexing transmission systems.   5. The transmission data sequence according to claim 1, wherein a timing at which a bit having a delay time of 0 in the bit interleaving appears immediately after the spreading code synchronization signal for the plurality of transmission data sequences. Code division multiplexing transmission system. Regarding the synchronization signal, the number of frames in one superframe is an integer number of TS packets defined by MPEG-2 Systems, regardless of the coding rate of the convolutional codes of the plurality of transmission data sequences. Select as
The leading edge of the punctured pattern of the synchronization byte of the TS packet and the punctured code defined by MPEG-2 Systems of each of the plurality of transmission data sequences is made to correspond to a predetermined position of the first frame in the one superframe of the synchronization signal. 5. The code division multiplexing transmission system according to claim 1, wherein the code division multiplexing transmission system is used. A receiving apparatus for receiving a code division multiplexed signal transmitted by the code division multiplexing transmission system according to claim 1 or 2,
For code division multiplex transmission, receiving the frequency-spread-modulated synchronization signal, demodulating it with a known spreading code, and reproducing a spreading code synchronization signal, information on the structure of a transmission data sequence or information on synchronization Receiver device. A receiving apparatus for receiving a code division multiplexed signal transmitted by the code division multiplexing transmission system according to claim 3 or 4,
For code division multiplex transmission characterized in that it receives the frequency-spread-modulated synchronization signal, demodulates it with a known spreading code, and regenerates the spreading code synchronization signal, all or information common to a specific receiving terminal Receiver device. A receiving apparatus for receiving a code division multiplexed signal transmitted by the code division multiplexing transmission system according to claim 5,
By using the parameter information of the coding rate or interleaving length of each of the plurality of transmission data sequences included in the information on the configuration of the transmission data sequence, error correction or deinterleaving of an arbitrary transmission data sequence is performed. The receiving apparatus for code division multiplexing transmission according to claim 15, wherein the receiving apparatus performs processing. A receiving apparatus for receiving a code division multiplexed signal transmitted by the code division multiplexing transmission system according to claim 6,
Performing error correction or deinterleave synchronization of an arbitrary transmission data sequence by using a synchronization word necessary for error correction or interleaving synchronization of each of the plurality of transmission data sequences included in the information related to synchronization of the transmission data sequence The receiving device for code division multiplexing transmission according to claim 15. A receiving device for receiving a code division multiplexed signal transmitted by the code division multiplexing transmission system according to claim 7,
A timing of error correction or deinterleaving is obtained by obtaining a synchronization word transmission period necessary for error correction or interleave synchronization in an arbitrary transmission data sequence from a transmission period of a synchronization word included in the synchronization signal. 16. The receiver for code division multiplex transmission according to claim 15. A receiving apparatus for receiving a code division multiplexed signal transmitted by the code division multiplexing transmission system according to claim 8,
Separately acquiring the presence position information of the own device, determining whether the own device is applicable from the area identification information included in the common information of the synchronization signal, and receiving and reproducing the common information if applicable The receiving apparatus for code division multiplexing transmission according to claim 16. A receiving apparatus for receiving a code division multiplexing signal transmitted by the code division multiplexing transmission system according to claim 9,
Separately obtains the registered group information of its own device, determines whether the registered group of its own device falls under the group identification information included in the common information of the synchronization signal, and receives the common information if applicable 17. The code division multiplexing transmission receiver according to claim 16, wherein the receiver is reproduced. A receiving apparatus for receiving a code division multiplexing signal transmitted by the code division multiplexing transmission system according to claim 10,
17. The receiving apparatus for code division multiplexing transmission according to claim 16, wherein the receiving apparatus is activated by an activation signal prompting activation of a receiving terminal included in the common information. A receiving apparatus for receiving a code division multiplexed signal transmitted by the code division multiplexing transmission system according to claim 11,
16. The depth of bit interleaving in an arbitrary transmission data sequence is obtained from the number of spreading code synchronization signals in one frame of the synchronization signal, and deinterleaving processing of the transmission data sequence is performed. 16. A receiver for a code division multiplex transmission system according to 16. A receiving apparatus for receiving a code division multiplexed signal transmitted by the code division multiplexing transmission system according to claim 12,
17. The code division multiplexing transmission system according to claim 15 or 16, wherein immediately after the spreading code synchronization signal is determined as a bit having a bit interleaving delay time of 0, and a deinterleaving process of the transmission data sequence is performed. Receiver device.   5. A transmission apparatus used in the code division multiplex transmission system according to claim 1.

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